(1) Field of the Invention
The present invention relates to anthraquinones which have anticancer or antitumor activity and which are useful for inhibiting growth of cancer cells and tumors in vitro or in vivo. The anthraquinones have the general chemical formula: wherein R1 is selected from the group consisting of hydrogen, alkyl, and substituted alkyl; R2 is a group containing 1-12 carbons selected from the group consisting of alkyl, substituted alkyl, aldehyde, hydroxy, hydroxymethyl, acid group, carbohydrate and combinations thereof; and R3 is a group containing 1 to 12 carbons selected from the group consisting of methyl, alkyl, substituted alkyl, aldehyde, hydroxy, hydroxymethyl, acid group, carbohydrate, and combinations thereof in an. The preferred anthraquinones are 1-hydroxy-2-acetyl-3,6-methyl anthraquinone, 2-acetyl-3,6-methyl anthraquinone monoacetate, 1-hydroxy-2-acetyl-3,7-methyl anthraquinone, 2-acetyl-3,7-methyl anthraquinone monoacetate, 1,2,8-trihydroxy-3-methyl anthraquinone, 1,8-dihydroxy-2-O-β-D-glucopyranoside anthraquinone, 1,2,8-trihydroxy-3-hydroxymethyl anthraquinone, and 1,8-dihydroxy-3-carboxy anthraquinone.
(2) Description of Related Art
Many anthraquinone derivatives are potent anticancer or antitumor drugs. The following are examples of U.S. patents which disclose the use of particular anthraquinones as anticancer agents.
U.S. Pat. No. 6,465,522 to Potter et al. discloses of anticancer drugs comprising anthraquinones linked to an alkylating agent.
U.S. Pat. No. 5,733,880 to Mincher discloses particular anthracene derivatives for use as anticancer agents.
U.S. Pat. No. 5,668,172 to Gallagher et al. discloses particular anthraquinones which can be used as anticancer agents.
U.S. Pat. No. 5,652,265 to Vittori et al. discloses the synthesis of the anthraquinone Rhein for use as an antitumor agent.
U.S. Pat. Nos. 5,091,385, 5,177,073, and 5,489,590 to Gulliya et al. disclose a therapeutic mixture comprising a photoactive compound which is capable of killing tumors when activated prior to use with an activating agent such as a chemical, radiation (preferably, irradiation with a laser), gamma rays, or electrons from an electropotential device. The photoactive compounds include a general suggestion of anthraquinones.
In light of the above, there remains a need for novel compounds with anticancer or antitumor activity to increase the arsenal of drugs for combating cancers in warm-blooded animals, including humans.